Evaluation Of Tissue Perfusion Research Articles

Incisional negative pressure wound therapy (PrevenaTM) vs. conventional post-operative dressing after immediate breast reconstruction: a randomized controlled clinical trial

BackgroundSurgical complications following breast reconstruction remain a significant concern. This study aimed to investigate if incisional negative pressure wound therapy (iNPWT) using Prevena™ provides superior wound treatment for patients undergoing immediate breast reconstruction (IBR) compared to conventional postoperative dressing. Additionally, we investigated whether intraoperative indocyanine green angiography (ICG-A) could predict and prevent postoperative complications.MethodsA randomized controlled study (RCT) comprising 39 patients was conducted. The primary outcome was time until surgical drain removal. ICG-A was applied to evaluate tissue perfusion and compared to rate of postoperative complications. Patients were followed for one year, including postoperative complications, quality of life (QoL), scar evaluation, incidence of lymphedema and timely administration of adjuvant therapy.ResultsNo significant differences were observed in time to surgical drain removal, hospitalization or incidence of postoperative complications between the two groups. Analysis revealed no significant association between ICG-A results and postoperative complications. After one year, both groups exhibited similar QoL and satisfaction with scars. One patient developed lymphedema during follow-up, and adjuvant treatment was timely administered in 82%.ConclusionsThis RCT investigated iNPWT by Prevena™ compared to conventional postoperative dressing in IBR using implants or tissue expanders. ICG-A was applied to assess tissue perfusion and compared to postoperative complications. We did not find any significant differences in recovery time, hospitalization duration, postoperative complication rates, QoL, or scar satisfaction between the two groups within a one-year follow-up. Additionally, there were no significant association between ICG-A and postoperative complications. Larger randomized studies incorporating intraoperative ICG-A are needed to obtain higher quality data.Level of Evidence: Level I, Risk/Prognostic

Is Kinesio taping acutely effective for peripheral tissue perfusion in women with mild to moderate chronic venous insufficiency? A randomized controlled trial

Objective To evaluate the acute effect of Kinesio Taping® (KT) on peripheral tissue perfusion in women with chronic venous insufficiency (CVI). Methods: This randomized, double-blind controlled trial included 59 women with mild to moderate CVI. They were randomized to a control group (n = 23; 54.08 ± 9.04 years) and KT group (n = 36; 55.87 ± 9.97 years). Near-infrared spectroscopy was positioned in the medial gastrocnemius muscle for assessment of resting tissue perfusion 48 h after the first day of evaluation and after placement of the Kinesio Taping® tape. The evaluation also consisted of performing movements of the plethysmography examination. To verify the comparisons of pre- and post-Kinesio Taping® data, the variation delta was used for analysis. Mann–Whitney U test was performed an an alpha of 5% was considered statistically significant. Results: There wasn't a significant difference between groups regarding the peripheral tissue perfusion evaluation variables Peripheral Oxygen Saturation Difference – DELTA_SPO2: (KT Group 3.21 (0.84–3.62); Control 2.21 (1.59–4.83), p = 0.219) and Difference in deoxygenate hemoglobin values – DELTA_HHB (units) KT Group -0.62 (-2.14–0.67); Control Group -0.07 (-2.15–2.62) p = 0.238). Despite the lack of statistical significance, the KT group had a 785.7% greater drop in HHB values than the control group. Conclusions: Acute use of Kinesio Taping® in women with CVI did not significantly alter tissue perfusion of calf muscles. However, it was possible to observe percentage differences in venous retention to be considered from a clinical point of view

Clinical evaluation of peripheral tissue perfusion as a predictor of mortality in sepsis and septic shock in the intensive care unit: Systematic review and meta-analysis

ObjectiveTo determine the diagnostic performance of the clinical evaluation of peripheral tissue perfusion in the prediction of mortality. DesignSystematic review and meta-analysis. SettingIntensive care unit. Patients and participantsPatients with sepsis and septic shock. InterventionsStudies of patients with sepsis and/or septic shock that associated clinical monitoring of tissue perfusion with mortality were included. A systematic review was performed by searching the PubMed/MEDLINE, Cochrane Library, SCOPUS, and OVID databases. Main variables of interestThe risk of bias was assessed with the QUADAS-2 tool. Sensitivity and specificity were calculated to evaluate the predictive accuracy for mortality. Review Manager software version 5.4 was used to draw the forest plot graphs, and Stata version 15.1 was used to build the hierarchical summary receiver operating characteristic model. ResultsThirteen studies were included, with a total of 1667 patients and 17 analyses. Two articles evaluated the temperature gradient, four evaluated the capillary refill time, and seven evaluated the mottling in the skin. In most studies, the outcome was mortality at 14 or 28 days. The pooled sensitivity of the included studies was 70%, specificity 75.9% (95% CI, 61.6%–86.2%), diagnostic odds ratio 7.41 (95% CI, 3.91–14.04), and positive and negative likelihood ratios 2.91 (95% CI, 1.80–4.72) and 0.39 (95% CI, 0.30–0.51), respectively. ConclusionsClinical evaluation of tissue perfusion at the bedside is a useful tool, with moderate sensitivity and specificity, to identify patients with a higher risk of death among those with sepsis and septic shock. RegistrationPROSPERO CRD42019134351.

NIR ICG-Enhanced Fluorescence: A Quantitative Evaluation of Bowel Microperfusion and Its Relation to Central Perfusion in Colorectal Surgery

Background: To date, no standardized protocols nor a quantitative assessment of the near-infrared fluorescence angiography with indocyanine green (NIR-ICG) are available. The aim of this study was to evaluate the timing of fluorescence as a reproducible parameter and its efficacy in predicting anastomotic leakage (AL) in colorectal surgery. Methods: A consecutive cohort of 108 patients undergoing minimally invasive elective procedures for colorectal cancer was prospectively enrolled. The difference between macro and microperfusion (ΔT) was obtained by calculating the timing of fluorescence at the level of iliac artery division and colonic wall, respectively. Results: Subjects with a ΔT ≥ 15.5± 0.5 s had a higher tendency to develop an AL (p < 0.01). The ΔT/heart rate interaction was found to predict AL with an odds ratio of 1.02 (p < 0.01); a cut-off threshold of 832 was identified (sensitivity 0.86, specificity 0.77). Perfusion parameters were also associated with a faster bowel motility resumption and a reduced length of hospital stay. Conclusions: The analysis of the timing of fluorescence provides a quantitative, easy evaluation of tissue perfusion. A ΔT/HR interaction ≥832 may be used as a real-time parameter to guide surgical decision making in colorectal surgery.

Peripheral Blood Mononuclear Cells: A New Frontier in the Management of Patients with Diabetes and No-Option Critical Limb Ischaemia.

The current study aimed to evaluate the effectiveness of peripheral blood mononuclear cell (PB-MNC) therapy as adjuvant treatment for patients with diabetic foot ulcers (DFUs) and no-option critical limb ischaemia (NO-CLI). The study is a prospective, noncontrolled, observational study including patients with neuro-ischaemic DFUs and NO-CLI who had unsuccessful revascularization below the ankle (BTA) and persistence of foot ischaemia defined by TcPO2 values less than 30 mmHg. All patients received three cycles of PB-MNC therapy administered through a "below-the-ankle approach" in the affected foot along the wound-related artery according to the angiosome theory. The primary outcome measures were healing, major amputation, and survival after 1 year of follow-up. The secondary outcome measures were the evaluation of tissue perfusion by TcPO2 and foot pain defined by the numerical rating scale (NRS). Fifty-five patients were included. They were aged >70 years old and the majority were male and affected by type 2 diabetes with a long diabetes duration (>20 years); the majority of DFUs were infected and nearly 90% were assessed as gangrene. Overall, 69.1% of patients healed and survived, 3.6% healed and deceased, 10.9% did not heal and deceased, and 16.4% had a major amputation. At baseline and after PB-MNC therapy, the TcPO2 values were 17 ± 11 and 41 ± 12 mmHg, respectively (p < 0.0001), while the pain values (NRS) were 6.8 ± 1.7 vs. 2.8 ± 1.7, respectively (p < 0.0001). Any adverse event was recorded during the PB-MNC therapy. Adjuvant PB-MNC therapy seems to promote good outcomes in patients with NO-CLI and neuro-ischaemic DFUs.

A conceptual review on reconstructive peri-implantitis therapy: Challenges and opportunities.

The current strategies to reconstruct lost peri-implant tissues due to the disease have been largely unpredictable. The aim of this conceptual review is to discuss relevant biological and biomechanical challenges of applying reconstructive means to treat peri-implantitis. Additionally, opportunities to improve treatment predictability are presented. A narrative review was conducted to fulfill the aim. The four interrelated negative conditions hampering effective reconstruction are: inferior tissue perfusion, unfavorable bone topography, ineffective surface treatment, and unstable wound. First, peri-implant tissues resemble scars with reduced cellularity and vascularity, coupled with the absence of the periodontal ligament plexuses and the avascular implant and biomaterials, maintaining primary closure is a challenge, which is critical for regeneration. Second, defect morphology and bone topography surrounding implants determine the reconstructive potential. Unfortunately, noncontained defects are frequently encountered, with a combination of suprabony (horizontal bone loss) and infrabony (vertical usually involving circumferential bone loss) defects. Third, current attempts for implant surface decontamination are insufficient due to inaccessible macrostructure and rough surfaces in the micro-scale. Histologic evaluation has shown bacteria aggregation and calcified deposits around implants. Lastly, wound stability is difficult to achieve due to inherent soft tissue biomechanical quality and quantity deficiencies and mobile bone particulates. Opportunities to tackle the abovementioned challenges include the use of novel imaging technologies, such as high-frequency dental ultrasound and laser speckle imaging to evaluate tissue perfusion, soft tissue quality/quantity, and bone topography pre-surgically. The use of the operating microscope could allow better visualization and removal of etiologic factors. Strategies to improve soft tissue quality may include preoperative control of soft tissue inflammation and the potential use of biologics. Methods such as fixation to stabilize the biomaterials could be beneficial. A more nuanced understanding of the current challenges and opportunities can lead to more effective preoperative and postoperative care protocols, ultimately improving the success rate of reconstructive procedures.

Indocyanine Green in Bariatric Surgery: a Systematic Review.

Indocyanine green (ICG) is a fluorescent dye that can be used intraoperatively to assess tissue perfusion, as well as perform leak testing. This study aims to summarize published manuscripts on outcomes of ICG use and reduction of complications compared to traditional leak test and tissue perfusion evaluation. A PubMed search using "ICG and bariatric surgery," "ICG and gastric sleeve," "ICG and gastric bypass," and "ICG and revisional bariatric surgery" was performed. The proportion of patients who underwent an intraoperative decision change due to ICG was 3.8% (95% CI: 2.0 to 7.2%). ICG fluorescent imaging in bariatric surgery is a valuable tool, and further studies are needed to confirm its utility for routine use in both standard or complex cases (PROSPERO #418126).

Use of Near-InfraRed Spectroscopy (NIRS) during Vascular Occlusion Test (VOT) for predicting an increase in oxygen consumption after fluid challenge in circulatory shock patients

Background: The goal of fluid challenge (FC) is to increase cardiac output (CO) and oxygen delivery (DO2) (known as fluid responders) to correct tissue hypoxia. To optimize fluid administration, fluid challenge (FC) during dependence of oxygen consumption on oxygen delivery (VO2/DO2 dependency) would correct tissue hypoxia confirmed by an increase of oxygen consumption (VO2) and oxygen delivery (DO2) after FC (known as VO2 responders) and get more benefit from a reduction in tissue hypoxia. Markers of anaerobic metabolisms, such as blood lactate concentration or the ratio of venous-arterial CO2 tension difference (P(cv-a)CO2) over arterial-to-venous oxygen content difference (C(a-cv)O2), can predict VO2 responders but still have several limitations. Therefore, near-infrared spectroscopy (NIRS) has been developed to evaluate tissue perfusion, presented as tissue oxygen saturation (StO2), at the bedside. Combining StO2 with the vascular occlusive test (VOT) and introducing a short period of forearm ischemia is a non-invasive technique to examine microvascular alterations at the bedside. However, a study validating the ability of these variables to predict VO2 response has not been conducted. Methods: We plan to conduct a single-center prospective study on circulatory failure patients. The cardiac index (CI), oxygen delivery (DO2), oxygen consumption (VO2), arterial lactate, central venous oxygen saturation (ScvO2), ratio of venous-arterial carbon dioxide tension to arterial-to-central venous oxygen content difference (P(cv-a)CO2/ C(a-cv)O2), and tissue oxygen saturation measured by near-infrared spectroscopy (NIRS) probe during vascular occlusion test variables (NIRS-VOT variables) will be collected before and after the fluid challenge. Hypothesis: We hypothesize that markers of reactive hyperemia by NIRs will predict an increase in VO2 after FC in patients with circulatory shock. Ethics: The study protocol has been approved by the ethics committee of the faculty of medicine, Ramathibodi Hospital, Mahidol University (COA. MURA2022/80).

Clinical evaluation of peripheral tissue perfusion as a predictor of mortality in sepsis and septic shock in the intensive care unit: Systematic review and meta-analysis

ObjectiveTo determine the diagnostic performance of the clinical evaluation of peripheral tissue perfusion in the prediction of mortality. DesignSystematic review and meta-analysis. SettingIntensive care unit. Patients and participantsPatients with sepsis and septic shock. InterventionsStudies of patients with sepsis and/or septic shock that associated clinical monitoring of tissue perfusion with mortality were included. A systematic review was performed by searching the PubMed/MEDLINE, Cochrane Library, SCOPUS, and OVID databases. Main variables of interestThe risk of bias was assessed with the QUADAS-2 tool. Sensitivity and specificity were calculated to evaluate the predictive accuracy for mortality. Review Manager software version 5.4 was used to draw the forest plot graphs, and Stata version 15.1 was used to build the hierarchical summary receiver operating characteristic model. ResultsThirteen studies were included, with a total of 1667 patients and 17 analyses. Two articles evaluated the temperature gradient, four evaluated the capillary refill time, and seven evaluated the mottling in the skin. In most studies, the outcome was mortality at 14 or 28 days. The pooled sensitivity of the included studies was 70%, specificity 75.9% (95% CI, 61.6%–86.2%), diagnostic odds ratio 7.41 (95% CI, 3.91–14.04), and positive and negative likelihood ratios 2.91 (95% CI, 1.80–4.72) and 0.39 (95% CI, 0.30–0.51), respectively. ConclusionsClinical evaluation of tissue perfusion at the bedside is a useful tool, with moderate sensitivity and specificity, to identify patients with a higher risk of death among those with sepsis and septic shock. RegistrationPROSPERO CRD42019134351.

Indocyanine Green (ICG)-Guided Onlay Preputial Island Flap Urethroplasty for the Single-Stage Repair of Hypospadias in Children: A Case Report

First described by Duckett in 1981, and initially employed for the surgical correction of mid-penile hypospadias, the onlay preputial island flap urethroplasty has progressively gained increasing popularity, extending its indication to proximal forms. However, with the complexity of the penile anomaly, the rate of postoperative complications related to poor tissue perfusion (including skin and glans dehiscence, urethral stenoses, and fistulas) has also increased. Conventionally, the visual assessment of the onlay preputial island flap is the only option available to establish the appropriate tissue vascularization during surgery. To this end, we have first introduced the EleVision IR system (Medtronic Ltd., Hong Kong, China) to assess the vascular perfusion of the preputial island flap in a 13-month-old boy undergoing the onlay urethroplasty for the surgical correction of a mid-shaft hypospadias. This was possible 80 s after the intravenous injection of indocyanine green (ICG, 0.15 mg/kg, Diagnostic Green GmbH, Munich, Germany). ICG-based laser angiography helped define the proximal resection margin of the preputial flap, and proved to be safe, effective, and easy to employ. This innovative intraoperative imaging modality can be considered a useful adjunct for tissue perfusion evaluation and intraoperative decision-making during the onlay preputial island flap urethroplasty in children.

Intraarterial Four-dimensional CT Angiography with Soft Tissue Perfusion Evaluation in Diabetic Feet.

Intraarterial Four-dimensional CT Angiography with Soft Tissue Perfusion Evaluation in Diabetic Feet.

PD06-08 TAKING THE SUBJECTIVITY OUT OF INTRAOPERATIVE MANAGEMENT OF TESTICULAR TORSION: CREATING A STANDARDIZED PROTOCOL FOR USE OF INDOCYANINE GREEN

You have accessJournal of UrologyCME1 Apr 2023PD06-08 TAKING THE SUBJECTIVITY OUT OF INTRAOPERATIVE MANAGEMENT OF TESTICULAR TORSION: CREATING A STANDARDIZED PROTOCOL FOR USE OF INDOCYANINE GREEN Amanda Raines, Nicolas Fernandez, Jennifer Ahn, Mark Cain, Byron Joyner, Kathleen Kieran, Paul Merguerian, Hailey Silverii, and Margarett Shnorhavorian Amanda RainesAmanda Raines More articles by this author , Nicolas FernandezNicolas Fernandez More articles by this author , Jennifer AhnJennifer Ahn More articles by this author , Mark CainMark Cain More articles by this author , Byron JoynerByron Joyner More articles by this author , Kathleen KieranKathleen Kieran More articles by this author , Paul MerguerianPaul Merguerian More articles by this author , Hailey SilveriiHailey Silverii More articles by this author , and Margarett ShnorhavorianMargarett Shnorhavorian More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003230.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The current standard of care to determine testicular viability in testicular torsion is surgeon’s subjective assessment. Studies on objective means to assess testicular perfusion after detorsion are lacking. Indocyanine green (ICG) is a fluorescent dye which has been widely used to evaluate tissue perfusion. To date use of ICG in testicular torsion has been limited to case reports with no series or protocols yet published. We aimed to develop and implement a standardized protocol for the use of ICG in testicular torsion and evaluate the effectiveness of ICG as an objective tool to assess testicular perfusion. METHODS: This was a single institution pilot study on the use of ICG in testicular torsion. A useable standardized protocol for use of ICG in testicular torsion was developed and implemented. The Stryker SPY PHI system and novel quantification software, SPY-QP, were used for ICG imaging. The protocol development was an adaptive process. The finalized protocol is detailed in Figure 1. RESULTS: ICG was used in 17 cases of testicular torsion with 13 undergoing orchiopexy and 4 undergoing orchiectomy. Of the 4 testes which were removed, we noted no to very low ICG uptake with SPY-QP measurements of 0-7% when compared to a mean ICG uptake in the orchiopexy group of 74.5% (p= 0.003) (Table 1). The pathology of all four showed hemorrhagic necrosis. At early post operative follow up there was no evidence of testicular atrophy in those that underwent orchiopexy. There were no intraoperative complications or adverse reactions to ICG. CONCLUSIONS: Our institution successfully developed and implemented a standardized protocol for ICG use in testicular torsion. Early results indicate our protocol provides objective and quantitative assessment of testicular perfusion. We think this technology is a useful adjunct in the surgical management of testicular torsion and can aid in surgical decision making particularly in equivocal cases. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e158 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Amanda Raines More articles by this author Nicolas Fernandez More articles by this author Jennifer Ahn More articles by this author Mark Cain More articles by this author Byron Joyner More articles by this author Kathleen Kieran More articles by this author Paul Merguerian More articles by this author Hailey Silverii More articles by this author Margarett Shnorhavorian More articles by this author Expand All Advertisement PDF downloadLoading ...

Real-Time Assessment of Tissue Oxygen Saturation Using a Novel Oximeter During Revascularization for Acute Limb Ischemia: A Case Report

Emergency surgery was performed to treat acute lower limb ischemia caused by heart thromboembolism and concomitant popliteal artery aneurysm. Using a near-infrared spectroscopy oximeter, regional tissue oxygen saturation (rSO2) was monitored to assess the tissue perfusion pre-, intra-, and postoperatively. rSO2 values did not increase sufficiently following thromboembolectomy of the superficial femoral artery, but they dramatically recovered after additional popliteal-anterior tibial bypass surgery. The affected limb was successfully salvaged. rSO2 monitoring was easily measured intraoperatively, which might be beneficial in evaluating tissue perfusion in patients with acute limb ischemia.

Evaluation of tissue perfusion by indocyanine green fluorescein angiography in patients with neuroischemic diabetic foot syndrome after endovascular treatment

To evaluate the fluorescence angiography (FA) parameters with Indocyanine green (ICG) and their dynamics in diabetic foot patients after endovascular treatment. A single-center prospective non-blinded study was conducted with the inclusion of 47 diabetic foot patients with Chronic limb-threatening ischemia (CLTI). TcPO2 and FA-ICG were done before and after angioplasty. Zones of interest were selected for FA-ICG: the area of minimum and maximum fluorescence, the area of of the largest part of the foot. Also presented are the parameters of FA ICG: Tstart (sec) - the time of occurrence of min fluorescence (Istart, unit) in the zone of interest after the introduction of ICG; Tmax (sec) - the time to achieve max fluorescence (Imax, unit) after the introduction of ICG; Tmax -Tstart (sec) - the difference in the time of reaching Imax and Istart. The median TcPO2 values indicated the presence of CLTI before revascularization. Technical success of revascularization was achieved in 45 patients. In the postoperative period, statistically significant changes in TcPO2 and Tstart, Tmax, Tmax-Tstar were obtained. A reduction in the time to reach the ICZ to the zones of interest was noted. FA-ICG evaluate the visual and quantitative characteristics of perfusion of soft tissues of the foot. Reducing the time to reach the fluorescent substance in the areas of interest makes it possible to assume the restoration of the main blood flow to the foot. Further investigations are warranted to determine threshold values to predict wound healing and indications for revascularization.

Measurement of tissue oxygen saturation during arthroscopic surgery of knee with a tourniquet.

Tourniquets provide better tissue visibility during arthroscopic surgery. However, multiple postoperative adverse events associated with ischemia may be caused by excessive inflation pressure and duration. We aimed to evaluate the degree of tourniquet-induced ischemia using a noninvasive continuous real-time monitoring method and the relationship between changes in tissue oxygen saturation (StO2) and blood biochemical markers of ischemic injuries in patients undergoing arthroscopic knee surgery. This was a prospective observational study using near-infrared spectroscopy (NIRS). Data were collected from 29 consecutive patients who underwent arthroscopic procedures. Twenty-five patients underwent anterior cruciate ligament reconstruction, and four underwent meniscal repair. We investigated tourniquet-induced changes in StO2, monitored using NIRS, and blood biochemical markers of ischemic injuries. A significant decrease in the mean StO2 from the baseline was observed during tourniquet inflation in the operative legs. The average decrease in the mean StO2 was 58%. A comparison of mean StO2 between the nonoperative and operative legs before tourniquet deflation showed that mean values of StO2 in the operative legs were significantly lower than those in the nonoperative legs. No significant clinical relationships were observed between changes in StO2 and blood biochemical markers of ischemic injuries (creatine kinase) (p = 0.04, r = 0.38) or tourniquet duration (p = 0.05, r = 0.366). Our results demonstrated that StO2 could be used to evaluate tissue perfusion in real time but did not support the hypothesis that StO2 is a useful method for predicting the degree of tourniquet-induced injury during arthroscopic knee surgery.

Indocyanine green near infrared-guided surgery in children, adolescents, and young adults with otolaryngologic malignancies

ObjectiveHead and neck cancers represent critical challenges due to the restricted anatomical space in children and the proximity of critical neurovascular structures which can compromise complete tumor resection. Applications of Indocyanine green (ICG) near infrared (NIR) fluorescent image-guided surgery (FGS) have recently expanded into the pediatric population, emphasizing its relevance for tumor delineation and evaluation of tissue perfusion. The objectives of the present study are twofold. First, we aim to assess the role of ICG NIR imagery in identifying neoplastic disease and second, to evaluate its role as an adjunct to identify metastatic deposits in cervical lymph node in children, adolescents, and young adults with head and neck cancers. MethodsEight patients with head and neck malignancies underwent ICG NIR FGS, between January 2019 and November 2021. ICG NIR findings were compared with preoperative cross-sectional imaging and results of operative tissue pathology analyses. ResultsAll primary tumors were identified on preoperative imaging and intraoperatively with ICG NIR; however, for one case, extension of tumor was revealed with ICG NIR and confirmed by histopathological examination but was not otherwise visible on preoperative imaging or with naked eye visual and tactile assessment. ICG NIR assisted the decision process in a difficult case for which curative resection, without significant functional morbidity and potential mortality, was unrealistic. Although ICG NIR evaluation of the surgical bed did not display residual tumor, margins were found positive in two cases. ICG NIR evaluation for local metastases changed the surgical strategy in one patient by prompting conversion to bilateral neck dissections. The sensitivity of preoperative multimodality imaging to identify cervical levels of invasion was 75% with a specificity of 70%, a PPV of 33%, a NPV of 78% and an accuracy of 72%. The ICG NIR sensitivity was 83%, its specificity was 88% with a PPV of 91%, a NPV of 80% and an accuracy of 86%. The combination of preoperative multimodality imaging with ICG NIR findings led to a sensitivity of 83%, specificity of 88% and accuracy of 86%. ConclusionThis case series provides a proof of concept of the feasibility of ICG NIR, as an adjunct in tumor and local metastases identification in young patients with head and neck tumors. It revealed to be feasible and safe for intra-operative tumor identification, thus guiding and facilitating resection. However, it showed some limitations in precise tumor margin assessment. The combination of preoperative multimodality imaging with ICG NIR findings improved local metastases localization.

Intraoperative fluorescence-guided perfusion assessment using indocyanine green-Increased safety in gastrointestinal anastomoses?

Insufficiency of gastrointestinal anastomoses represents arelevant risk of morbidity and mortality for affected patients. The perfusion quality of the ends of the intestine is the decisive parameter for ensuring sufficient healing of an anastomosis. Intraoperative fluorescence-guided perfusion assessment with indocyanine green is increasingly being used in modern visceral surgery to evaluate tissue perfusion prior to the fashioning of gastrointestinal anastomoses. This technique provides the possibility to distinguish between adequately and inadequately perfused tissue in order to place the anastomosis in the region with the best possible perfusion. Thus, surgeons have ameasuring instrument that enables an objective assessment of the perfusion quality of the tissue to be undertaken in addition to a purely subjective macroscopic visual assessment, in order to achieve abetter functional result for the patients. Currently, however, the value of this technique has not yet been conclusively clarified. The aim of this review article is to characterize the benefits of intraoperative fluorescence-guided perfusion assessment and to classify it with respect to its significance for routine clinical practice.

Spatial and temporal patterns in dynamic-contrast enhanced intraoperative fluorescence imaging enable classification of bone perfusion in patients undergoing leg amputation.

Dynamic contrast-enhanced fluorescence imaging (DCE-FI) classification of tissue viability in twelve adult patients undergoing below knee leg amputation is presented. During amputation and with the distal bone exposed, indocyanine green contrast-enhanced images were acquired sequentially during baseline, following transverse osteotomy and following periosteal stripping, offering a uniquely well-controlled fluorescence dataset. An unsupervised classification machine leveraging 21 different spatiotemporal features was trained and evaluated by cross-validation in 3.5 million regions-of-interest obtained from 9 patients, demonstrating accurate stratification into normal, suspicious, and compromised regions. The machine learning (ML) approach also outperformed the standard method of using fluorescence intensity only to evaluate tissue perfusion by a two-fold increase in accuracy. The generalizability of the machine was evaluated in image series acquired in an additional three patients, confirming the stability of the model and ability to sort future patient image-sets into viability categories.

Near-infrared fluorescence imaging during ex vivo lung perfusion: Noninvasive real-time evaluation of regional lung perfusion and edema

ObjectiveEx vivo lung perfusion (EVLP) is an excellent platform to evaluate donor lung function before transplantation, but novel methods are needed to accurately confirm transplant quality. Near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) has been used in various clinical perioperative applications to evaluate tissue perfusion. We used NIRF imaging during pig and human EVLP to evaluate donor lung perfusion and edema. MethodsPig lungs with various degrees of lung injury (n = 10) and human lungs rejected from clinical transplantation (n = 3) were imaged during EVLP using intravascular ICG and a SPY Elite (Stryker) NIRF imaging unit. Optimal ICG and imaging conditions, and perfusion and edema quantification methods, were established. Pig lung transplants with extended graft preservation (n = 5) and control native lungs (n = 6) were also imaged. ResultsA single ICG dose resulted in sustained donor lung NIRF throughout the EVLP. Even and homogenous ICG signal was demonstrated in areas of normal lung. Low NIRF was present in regions with poor tissue perfusion, and rapid, intense ICG accumulation occurred in damaged and edematous areas. Segmental perfusion defects were common in the peripheral and elevated regions of the lungs, and serial imaging showed gradual perfusion recovery during EVLP. Impaired microvascular reperfusion, indicated by a decreased NIRF ingress rate, was detected in transplanted pig lungs early after reperfusion. ConclusionsNIRF imaging enables noninvasive real-time evaluation of lung perfusion and edema during EVLP. Prospective clinical studies are needed to determine the role of NIRF imaging in donor lung assessment and selection, and prediction of posttransplant outcomes.

Clinical utility of near-infrared perfusion assessment of the gastric tube during Ivor Lewis esophagectomy.

Anastomotic leakage (AL) after Ivor Lewis esophagectomy with intrathoracic anastomosis carries a significant morbidity. Adequate perfusion of the gastric tube (GT) is an important predictor of anastomotic integrity. Recently, near infrared fluorescent (NIRF) imaging using indocyanine green (ICG) was introduced in clinical practice to evaluate tissue perfusion. We evaluated the feasibility and efficacy of GT indocyanine green angiography (ICGA) after Ivor Lewis esophagectomy. This retrospective analysis used data from a prospectively kept database of consecutive patients who underwent Ivor Lewis (IL) esophagectomy with GT construction for cancer between January 2016 and December 2020. Relevant outcomes were feasibility, ICGA complications and the impact of ICGA on AL. 266 consecutive IL patients were identified who matched the inclusion criteria. The 115 patients operated with perioperative ICGA were compared to a control group in whom surgery was performed according to the standard of care. ICGA perfusion assessment was feasible and safe in all 115 procedures and suggested a poorly perfused tip in 56/115 (48.7%) cases, for which additional resection was performed. The overall AL rate was 16% (43/266), with 12% (33/266) needing an endoscopic our surgical intervention and 6% (17/266) needing ICU support. In univariable and multivariable analyses, ICGA was not correlated with the risk of AL (ICGA:14.8% vs non-ICGA:17.2%, p = 0.62). However, poor ICGA perfusion of the GT predicted a higher AL rate, despite additional resection of the tip (ICGA poorly perfused: 19.6% vs ICG well perfused: 10.2%, p = 0.19). ICGA is safe and feasible, but did not result in a reduction of AL. The interpretation and necessary action in case of perioperative presence of ischemia on ICGA have yet to be determined. Prospective randomized trials are warranted to analyze its benefit on AL in esophageal surgery. Trial registration Ethical approval for a prospective esophageal surgery database was granted by the Ethical committee of the Ghent University Hospital. Belgian registration number: B670201111232. Ethical approval for this retrospective data analysis was granted by our institutional EC. BC-09216.